1. Field of the Invention
The present invention relates to presses and baling equipment, and more particularly to a reduced-maintenance rubber baler utilizing thermoplastic or polymer materials having low static and dynamic coefficients of friction to improve structural components such as press chamber liners and platen or ram head covers.
2. Description of the Related Art
Baling machines come in many shapes and sizes, and are used to transform loose materials into solid blocks having a variety of uses. In typical baling machines, such as the type used to bale rubber products, rubber or other compressible material is fed into a press chamber by a conveyor belt or by screw conveyor. The material is then compressed in the press chamber by a hydraulic ram having a ram head or platen until a relatively solid block is formed. The block is then ejected and the process is repeated to form additional blocks.
Many rubber baling machines utilize steel for the press chamber walls, press chamber liners, ram head or platen covers, and wear strips about the press or mold chamber. Steel fragments resulting from grinding and wear on these steel components often results in metal contamination of the rubber product. This contamination sometimes causes the product to be rejected for uses requiring rubber of high purity in which even trace amounts of metal render the blocks useless. Further problems arise because the liner plates are often simply metal sheets butted up against one another. Rubber can migrate between the corners or junctions between these plates, causing misalignment between the press chamber and the hydraulic ram. Rubber extrusion between the steel components also results in product loss.
Attempts have been made to combat these problems. For example, the wear strips in many presses are comprised of materials other than steel in order to reduce frictional wear of steel press chamber walls due to movement of the ram head. Without frequent and time-consuming maintenance, however, the wear strips often become worn to the point of causing the press to become misaligned. In turn, misalignment frequently results in scoring of the steel press chamber walls and product contamination. The maintenance required for these prior art baling machines therefore results in less than desirable overall operating costs.